1. Field of the Invention
The present invention relates in general to providing means for adequate ventilation for protective panels or covers used for protecting ornamental windows such as stained glass.
2. Description of the Prior Art
Ornamental windows, such as stained glass windows, represent an expensive investment for an individual or institution. These windows are typically on the exterior of buildings and as such are exposed to moisture, wind, excessive heat and vandalism. Repair of such windows can represent an enormous expense.
It is therefore common to employ protective panels for such windows, to not only protect the ornamental window from damage, but to provide an insulating or thermal barrier for the ornamental window. A protective covering is described in U.S. Pat. No. 5,993,925. Typically these protective coverings which are sometimes referred to as protective glazing, cover the ornamental window pattern in such a fashion that it corresponds to the window's geometric shape. These protective coverings or panels can comprise a wide diversity of transparent materials such as clear or tempered glass, acrylic, polycarbonate, as well as laminated or thermopane glass. These panels typically provide an airspace between the panel and ornamental window to provide a thermal barrier.
Unfortunately, the use of these panels often actually results in unintended and accelerated damage. It is not uncommon for these panels to be added without adequate ventilation. This allows the airspace created between the panel and window to cycle between superheated high temperatures and low temperatures relative to sun exposure. This constant cycling between high and low temperature in the airspace damages leaded stained glass windows by metal fatigue which weakens the leaded seams between the glass sections of the stained glass window. Moisture that may also inadvertently be trapped in the airspace represents a threat to the stained glass appearance, allows bacteria and microorganisms to multiply and damage the cemented portions, and accelerates the deterioration of the leaded joint. Non vented protective panels act as a solar box, cycling temperatures between 165 and 5 degrees Fahrrenheit and leaving the temperature at or near dewpoint for longer periods of time than would otherwise occur. Because of the various materials in the window i.e. glass, lead, wood and their respective and varied expansion coefficients, this temperature swing over time weakens the structure allowing bowing, weakening, and cracking.
It is therefore common for installers of these protective panels to drill holes in portions of the panel to provide some degree of air exchange with the exterior air. These holes however, reduce the aesthetic value of the protective panel and, for the most part, do not provide an adequate source of ventilation for the airspace. In addition, without some sort of filter device, these holes allow moisture, insects and debris to enter the space between the stained glass window and the protective panel. Therefore, this kind of ventilation does not address the problems posed by heat cycling and moisture between the protective panel and the window.
It is therefore an object of the present invention to provide a means for the ventilation of protective panels for ornamental windows that provides an adequate degree of air exchange with exterior or interior air, to avoid or at least minimize the problems posed by heat cycling and trapped moisture.
It is also an object of the present invention to provide venting means for the airspace between the protective panel and the ornamental window wherein venting means are included in the frame to avoid appearance issues with the cover.
It is a further object to provide venting means which provide directed air flow or air exchange in the airspace.
It is an object to provide venting means which may be included in the frame holding the protective panel and the stained glass window or in a perimeter frame holding just the protective paneling or in other frame elements such as mullions or muntins.
It is an objective of the present invention to provide venting means which adequately prevent moisture in the form of rain water and insects from entry.
These and other objects are achieved by the present invention described below.